prop size for older evinrude

[cool rock daddy]

cannot find serial # on motor bracket or anywhere else on motor,I need prop size info for 1977 evinrude 40 horse,thanks for your help,Bill in St.Pete FL.

[boats.net]

There were 8 different models in 1976 for the 40hp. 1976 is the closest year that offered the 40hp. I have randomly selected a 40hp in 1976, the following link will show you the propellers offered for that year from the manufacturer.
1976 40654R Evinrude / Johnson Evinrude GEARCASE Diagram and Parts

[cool rock daddy]

thank you very much